Kevin Hunt: Did Millions Of People Buy The Wrong Type Of Smoke Alarm?

Ninety-six percent of the country's homes have at least one smoke alarm, according to the National Fire Protection Association.

What kind do you have?

If it's not photoelectric it's the wrong kind, says Skip Walker, a home inspector from San Bruno, Calif., with a distinct day-night mission statement.

"I inspect by day," he says, "and try to get photoelectric alarms mandated by night."

Walker says that despite the installation of smoke alarms in more than 100 million homes in 30 years the chances of dying in a home fire have not changed much.

Consumers have three choices when buying smoke alarms: ionization, photoelectric and a device that combines the two technologies.

Most installed alarms, 90 percent, are ionization models best suited for detecting cooking fires and other fast-flame fires — fires that usually start when people are awake and can escape. Photoelectric alarms are more sensitive to smoldering fires in living rooms, bedrooms and kitchens, where heavy furniture, mattresses and synthetic countertops are more likely to burn slowly. These fires often start overnight, during sleep hours.

Smoldering fires, says Walker, account for only about 12 percent of fires but more than half of fire-related deaths and a third of fire-related injuries. Photoelectric alarms save lives, he says. Ionization alarms rarely save lives.

"National Institute of Standards and Technolory data tells us ionization alarms respond, in their tests, on average 30 minutes slower than a photoelectric in a smoldering fire," says Walker. "Thirty minutes."

Massachusetts, Rhode Island, Vermont, Maine and Iowa now require photoelectric alarms in homes. Connecticut's fire code requires residential properties to have a smoke alarm in each sleeping area, one outside sleeping areas and one each level, including the basement, but does not specify the type.

"We really don't do any recommending," says William Abbott, the state's fire marshal. "The code doesn't differentiate between which alarm that you would need. So we just go by what the fire code tells us."

So what type of alarm did Abbot install in his home?

"I have photoelectric in my house," he says. "That's what I ended up with."

Towns and cities also have local ordinances. Stamford, for instance, adopted stricter regulations following the 2011 Christmas Day fire that killed three young girls and their grandparents in a home with no working alarms. The city now requires a smoke detector and carbon monoxide detector outside each sleeping area and a smoke detector in each room used for sleeping.

What type do you have? Most people probably don't know. To identify an ionization alarm, look for a model number that includes the letter "I," Americum-241 or any mention of radioactive material. A photoelectric alarm often identifies itself as "photoelectric" or perhaps with a capital "P" somewhere on the device.

If prone to frequent nuisance tripping, it's almost certainly an ionization alarm. Kitchen or bathroom steam or a microwave can trigger an ionization alarm. After too many false alarms, homeowners often remove the battery, disabling the alarm.

"As soon as you have no functional alarm in a house, you double your chances of dying in a fire," says Walker. "That's where two-thirds of all deaths occur in fires — in homes where alarms aren't functional."

Walker says he became a photoelectric-alarm convert when Marc McGinn, the fire chief in nearby Albany — the first California city with an ordinance requiring photoelectric alarms — spoke to a group of home inspectors almost four years ago.

"I told him, 'You've got our attention," says Walker. "It's just criminal is the best word I can use to describe the situation. . . . His contention is that [ionization alarms] should be banned and recalled from the market. I would love that to happen."

But it won't, and Walker knows it.

"No one wants to admit they're bad because of the legal liability," he says. "If those things were recalled, the manufacturers would get sued into the Stone Ages. I'm talking 40,000 wrongful-death lawsuits and 200,000 serious-injury cases over the last 40 years. So what's the liability for that?"

Aside from slow response to smoldering fires and nuisance tripping, ionization alarms also had a 20 percent failure rate in a 2007 Underwriters Laboratories study that included did-not-trigger results in seven of eight tests using synthetic materials.

A combination alarm, with ionization's superior response to fast-flame fires and photoelectric's superior response to smoldering fires, would seem a smart compromise. But Walker cautions that combos, too, are susceptible to nuisance tripping. The Bottom Line, after installing a combination alarm in small home-theater room, discovered that the television's remote triggered the alarm. The only solution: removing the alarm's battery.

Consumer Reports, in its most recent tests, rated the dual-sensor Kidde PI9000 as the top-performing alarm.

"We recommend smoke alarms with dual smoke sensors because each type has detection strengths," says James McQueen, a Consumer Reports spokesman. "Admittedly, some detection might be more prone to false alarming in certain locations and for just those instances, a single detector-style alarm might be warranted."

The Kidde alarm costs about $25. Walker says he bought two photoelectric alarms at Costco for $23.

The Bottom Line: A photoelectric alarm is your best chance to avoid death in a house fire. A combination alarm is acceptable, but only if you keep the battery in it. Ionization alarms are better than nothing.